笔试题之交错数组 Java递归求解

题目: 将一个交错数据合并为一个一维数组
输入: strJaggedArray[][], 由多个一维数组(长度不定,个数不定)组成的交错数组
输出: strArray[], 由strJaggedArray[r][c]中的元素以"&"为分隔符拼合而成, 是strJaggedArray中数组元素的无重复组合(不考虑顺序)

举例:
输入: strJaggedArray[0]=new string[] {"we","are","student"};
      strJaggedArray[1]=new string[] {"say","what"};
输出: strArray[]={"we&say","we&what","are&say","are&what","student&say","student&what"}

输入: strJaggedArray[0]=new string[] {"cs","app"};
      strJaggedArray[1]=new string[] {"good","cool","dev"};
      strJaggedArray[2]=new string[] {"king","of","the","world"};
输出: strArray[]={"cs&good&king","cs&good&of","cs&good&the","cs&good&world","cs&cool&king","cs&cool&of","cs&cool&the","cs&cool&world",...}

 

好久没玩玩TopCoder了,工作时间不允许,看到这样的题目多多少少有种熟悉的感觉....,如果现在再打TopCoder的话,因该比去年进步了很多了吧........

本来是C#的题,不过最近学JAVA又没书看,只好找题做了...

 

public class ExchangeArray ...{

    /** *//**
     * @Auth Red_angelX
     * @param args
     */
    public static void main(String[] args) ...{
        // TODO Auto-generated method stub
        String[][] strJaggedArray = new String[3][];
        strJaggedArray[0] = new String[] ...{"cs","app"};
        strJaggedArray[1] = new String[] ...{"good","cool","dev"};
        strJaggedArray[2] = new String[] ...{"king","of","the","world"};
        String[] strArray = Exchange(strJaggedArray);
        for(int i=0; i< strArray.length ;i++)
        ...{
        System.out.println(strArray[i]);
        }
    }
    
    /** *//**
     * 函数
     * @param strJaggedArray
     * @return
     */
    public static String[] Exchange(String[][] strJaggedArray)
    ...{
        String[][] temp = DoExchange(strJaggedArray);
        return temp[0];        
    }
    
    /** *//**
     * 递归
     * @param strJaggedArray
     * @return
     */
    private static String[][] DoExchange(String[][] strJaggedArray)
    ...{
        int len = strJaggedArray.length;
        if(len >= 2)
        ...{            
            int len1 = strJaggedArray[0].length;
            int len2 = strJaggedArray[1].length;
            int newlen = len1*len2;
            String[] temp = new String[newlen];
            int Index = 0;
            for(int i=0;i<len1;i++)
            ...{
                for(int j=0;j<len2;j++)
                ...{
                    temp[Index] = strJaggedArray[0][i] + "&"+strJaggedArray[1][j];
                    Index ++;
                }
            }
            String[][] newArray = new String[len-1][];
            for(int i=2;i<len;i++)
            ...{
                newArray[i-1] = strJaggedArray[i];                            
            }
            newArray[0] = temp;
            return DoExchange(newArray);
        }
        else
        ...{
        return strJaggedArray;    
        }
    }

}